Recently, demands for a high-resolution and high-quality image have increased in various fields of applications. As an image has higher resolution and higher quality, an amount of data on the image increases more. Accordingly, when image data is transferred using media such as existing wired or wireless broadband lines or image data is stored in existing storage media, the transfer cost and the storage cost increases. In order to effectively transfer, store, and reproduce information on high-resolution and high-quality images, high-efficiency image compressing techniques may be utilized.
Inter prediction and intra prediction may be used to enhance image compression efficiency.
In the inter prediction, pixel values included in a current picture are predicted from previous or subsequent pictures of the current picture. In the intra prediction, pixel values included in a current picture are predicted using pixel information in the current picture.
In addition to the inter prediction and the intra prediction, a weighting value predicting technique for preventing degradation in image quality due to a variation in illumination or the like, an entropy encoding technique of assigning a short code to a symbol with a high appearance frequency and assigning a long code to a symbol with a low appearance frequency, and the like may be used for more efficient processes.